The Sultana photographed shortly before the explosion. Note all the paroled Union soldiers crowded onto the upper deck.

Photo from the Library of Congress (digital ID: cph.3a48909). The copyright for this image has expired. Image description from the Library of Congress:

"Photograph shows the overloaded steamboat Sultana on the Mississippi River the day before her boilers exploded and she sank on April 27th. The passengers included ca. 1,880 Union soldiers heading home at the end of the Civil War; more than 1,100 of these men died in the disaster."